I thought filaments produced photons/light waves as well. You took me to
light now you want to leave!
Come on I just want a good basic understand on what it is the the Tx
reflects the power , how it does it and a little simple math. My dad used
to say if you can't explain something you think you know to someone else it
might because you don't understand it yourself or lack command of the
language. In this case for me it's both.
73
Hank WD5JFR
"Cecil Moore" wrote in message
...
Henry Kolesnik wrote:
OK, if we shine a flashlight at a mirror the light bounces back and what
ever is caught by the reflector will be reflected. Take away the
reflector
and the reflection just keeps going. If someone can tell me what the
hot
filament does perhaps I can understand what happens in the finals, or
whatever.

The hot filament provides a source of electrons. How many
electrons are emitted depends on the instantaneous voltages
on the other elements, the plate and grids. Reflected waves
have an effect on those instantaneous voltages but IMO,
there's not much sense in pursuing the "filament" line of
reasoning.
--
73, Cecil http://www.qsl.net/w5dxp



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Henry Kolesnik wrote:
I thought filaments produced photons/light waves as well. You took me to
light now you want to leave!

Well, the light emitted by tube filaments is irrelevant to the RF
function. I use light examples because light and RF are both EM
waves and a lot more is known about light than about RF.

Come on I just want a good basic understand on what it is the the Tx
reflects the power , how it does it and a little simple math. My dad used
to say if you can't explain something you think you know to someone else it
might because you don't understand it yourself or lack command of the
language. In this case for me it's both.

What I am trying to say is that I don't know what happens inside
a transmitter. Under Z0-matched conditions, as with a tuner, I
believe that what happens inside a transmitter is pretty much
irrelevant. The transmitter sees its designed-for impedance and
that is essentially all that matters.

What I am willing to discuss in detail is what happens at a Z0-match
point (x) in an antenna system with reflections - something like the
following:

XMTR---51.5 ohm line---x---1/4WL 300 ohm line---1749 ohm load
100W -- 200W --
-- 0W -- 100W

For these typical conditions, all voltages and currents are either
in-phase or 180 degrees out of phase at the match point (x), which
makes a power analysis the most simple analysis of all.
--
73, Cecil http://www.qsl.net/w5dxp



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"Cecil Moore" wrote in message
...

What I am willing to discuss in detail is what happens at a Z0-match
point (x) in an antenna system with reflections - something like the
following:

what you are willing to discuss is irrelevent as it has nothing to do with
the original topic which was about what happens in the transmitter.


For these typical conditions, all voltages and currents are either
in-phase or 180 degrees out of phase at the match point (x), which
makes a power analysis the most simple analysis of all.

that should read "For these specific conditions", those conditions are
hardly 'typical', they are a very exactly contrived example which makes it
easy to compare powers. thus making the proper analysis of currents or
voltages seem unnecessary. taking simple cases like this and improperly
generalizing them is what leads to the worst mis-conceptions and circular
arguments in this group.

Dave wrote:

"Cecil Moore" wrote:
What I am willing to discuss in detail is what happens at a Z0-match
point (x) in an antenna system with reflections - something like the
following:

what you are willing to discuss is irrelevent as it has nothing to do with
the original topic which was about what happens in the transmitter.

Uhhhh Dave, the original topic is the Subject: line. If anything,
what happens inside a transmitter is the irrelevant subject since
appreciable reflections hardly ever reach the typical ham transmitter.

For these typical conditions, all voltages and currents are either
in-phase or 180 degrees out of phase at the match point (x), which
makes a power analysis the most simple analysis of all.

that should read "For these specific conditions", those conditions are
hardly 'typical', they are a very exactly contrived example which makes it
easy to compare powers.

No, those are typical conditions, where the ham radio antenna system
is tuned to a Z0-match by a tuner, either external or internal. It is
not a "very exactly contrived example" at all. It is absolutely typical
of any ham radio installation where the final amp sees close to a 1:1 SWR
and that is the great majority. At the Z0-match point at the input of
every properly tuned transmatch, the voltages and currents are either in
phase or 180 degrees out of phase. If you don't know that, it is no
wonder that you label my power analysis stuff as "contrived".
--
73, Cecil http://www.qsl.net/w5dxp



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"Cecil Moore" wrote in message
...
Dave wrote:

"Cecil Moore" wrote:
What I am willing to discuss in detail is what happens at a Z0-match
point (x) in an antenna system with reflections - something like the
following:

what you are willing to discuss is irrelevent as it has nothing to do
with
the original topic which was about what happens in the transmitter.

Uhhhh Dave, the original topic is the Subject: line. If anything,
what happens inside a transmitter is the irrelevant subject since
appreciable reflections hardly ever reach the typical ham transmitter.


here is the original:

I know that any power not dissipated by an antenna is reflected back to the
transmitter. Then the transmitter "reflects" this reflection back to
antenna, ad nauseum until its all gone. I also know that a short or an open
is required to reflect power and I'm searching for which it is, an open or a
short. I'm inclined to think it's a virtual open but I'm at a loss to
understand that and I wonder if someone has a good explanation or analogy
and some math wouldn't hurt.
tnx
Hank WD5JFR

obviously not about what is going on at some contrived transmission line
joint.


For these typical conditions, all voltages and currents are either
in-phase or 180 degrees out of phase at the match point (x), which
makes a power analysis the most simple analysis of all.

that should read "For these specific conditions", those conditions are
hardly 'typical', they are a very exactly contrived example which makes
it
easy to compare powers.

No, those are typical conditions, where the ham radio antenna system
is tuned to a Z0-match by a tuner, either external or internal. It is
not a "very exactly contrived example" at all. It is absolutely typical
of any ham radio installation where the final amp sees close to a 1:1 SWR
and that is the great majority. At the Z0-match point at the input of
every properly tuned transmatch, the voltages and currents are either in
phase or 180 degrees out of phase. If you don't know that, it is no
wonder that you label my power analysis stuff as "contrived".

of course it is contrived. no one uses loads of those exact impedances, or
lengths of coax like you do.

Dave wrote:

Cecil wrote:
Uhhhh Dave, the original topic is the Subject: line. If anything,
what happens inside a transmitter is the irrelevant subject since
appreciable reflections hardly ever reach the typical ham transmitter.

here is the original:

Are you saying that the original subject was wrong?

of course it is contrived. no one uses loads of those exact impedances, or
lengths of coax like you do.

Dave, have you ever heard of an example? What I posted is one
easy-to-understand example of virtually an infinite number of
possible examples of a Z0-match. If you like, here is another
example of a Z0-match:

XMTR------tuner---unknown length of feedline---unknown load
100W--
--0W

There is a Z0-match at the input of the tuner. All the voltages
and all the currents are very close to in-phase or 180 degrees
out of phase at the input of the tuner. Do you have the balls to
assert that the above configuration is "contrived"?

THE GREAT MAJORITY OF AMATEUR RADIO ANTENNA SYSTEMS ACHIEVE CLOSE
TO A Z0-MATCH!!! That means all the voltages and currents are close
to being in phase or 180 degrees out of phase. I'm sorry that technical
fact hairlips you. Since your hidden agenda is hidden, I can only
guess what it might be.
--
73, Cecil http://www.qsl.net/w5dxp



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"Cecil Moore" wrote in message
...
Dave wrote:

Cecil wrote:
Uhhhh Dave, the original topic is the Subject: line. If anything,
what happens inside a transmitter is the irrelevant subject since
appreciable reflections hardly ever reach the typical ham transmitter.

here is the original:

Are you saying that the original subject was wrong?

no, only that you ignored the body of the message and answered what you
wanted to discuss instead of what was asked.


of course it is contrived. no one uses loads of those exact impedances,
or
lengths of coax like you do.

Dave, have you ever heard of an example? What I posted is one
easy-to-understand example of virtually an infinite number of
possible examples of a Z0-match. If you like, here is another
example of a Z0-match:

XMTR------tuner---unknown length of feedline---unknown load
100W--
--0W

There is a Z0-match at the input of the tuner. All the voltages
and all the currents are very close to in-phase or 180 degrees
out of phase at the input of the tuner. Do you have the balls to
assert that the above configuration is "contrived"?

nope, that is a real world situation, but not the one under discussion.


THE GREAT MAJORITY OF AMATEUR RADIO ANTENNA SYSTEMS ACHIEVE CLOSE
TO A Z0-MATCH!!! That means all the voltages and currents are close
to being in phase or 180 degrees out of phase. I'm sorry that technical
fact hairlips you. Since your hidden agenda is hidden, I can only
guess what it might be.

so which is it, in phase or 180 degrees out of phase???